The present paper describes the fabrication and solar hydrogen production studies employing a new semiconductor-septum (SC-SEP) photoelectrode ns-TiO2-In2O3 admixed/Ti based photoelectrochemical solar cell. The current-voltage characteristics of the above SC-SEP cell revealed that an enhancement in short-circuit current (Isc) up to three times (5 similar to 18.6 mA cm(-2)). The rate of hydrogen production was found to change with variation in the concentration of the electrolyte in the dark compartment; e.g. for 1 M H2SO4 it is 6.0 lh(-1) m(-2) and for 6 M it is 14.6 lh(-1) m(-2). The optimum hydrogen production rate was found to be 14.6 lh(-1) m(-2) for 6 M H2SO4 and with a further increase in H2SO4 concentration. the hydrogen production rate was found to be invariant. In yet another part of our study instead of using new SC SEP solar cell design, we used a new material form such as ns-TiO2-VO2. The VO2 admired ns-TiO2 exhibited a high photo-current acid photo-voltage of 19.2 mA cm(-2) 680 mV, respectively. The ns-TiO2-VO2 electrode exhibited a higher hydrogen gas evolution rate of 16 l/h(1)/m(2). Evidences and arguments are put forward to show that, whereas for the bare ns-TiO2 electrode, the improvement in the performance of this photo-electrode compared with its original form was due to the higher quantum yield. In the case of ns-TiO2-In2O3 and ns-TiO2-VO2 photo-electrodes, the improvement is due to the improved spectral response resulting from decrease of energy band gap. (C) 2000 International Association for Hydrogen Energy.